Volume 7 Issue 3, March 2024

While skeletal editing stands as a powerful approach for simplifying synthetic procedures and obtaining complex molecules, viable methodologies remain limited. Now, a smart photoredox protocol, involving the insertion of carbon atoms into the indene core, gives access to a wide library of functionalized naphthalenes.

The lack of stability of critical raw material-free electrocatalysts during the oxygen evolution reaction in acidic electrolytes lies beneath the use of Ir-based electrocatalysts in polymeric water electrolysis. Here, a strategy to enhance γ-MnO₂ stability in acid is proposed. Theoretical and spectroscopic approaches reveal that increasing the fraction of O atoms in the appropriate position, namely O_pla, prevents Mn dissolution during water electrolysis.

The development of bimetallic catalysts is often hindered by the heavy workload of the classical trial-and-error method. Now, a distinct mechanism demonstrates that breaking down the net thermochemical reaction into the corresponding electrochemical half-reactions offers a facile approach to design bimetallic catalysts by analysing each putative half-reaction.

The electrochemical synthesis of ammonia via the lithium-mediated reduction of N₂ holds great promise to replace the carbon- and energy-intensive Haber–Bosch process. This Review discusses this approach and examines the critical role of the catalytic solid–electrolyte interphase formed on the electrode.

Ring-expanding carbon-atom insertion reactions are currently limited to the installation of few functional groups. Now researchers show the use of a radical carbyne precursor for the insertion of carbon atoms bearing varied functional groups to access 2-substituted naphthalenes from indene.

Precious-metal-free catalysts for water oxidation commonly suffer from low stability in acidic electrolytes. Now, by controlling the intergrowth of the γ-MnO₂ structure, it has been possible to achieve 2 A cm⁻² at 2 V and a stability of over 1,000 hours at 200 mA cm⁻² in a polymer electrolyte membrane electrolyser.

The mechanism by which bimetallic catalysts can outperform their monometallic counterparts is often unexplained. Now nitrate hydrogenation on bimetallic catalysts is shown to proceed via the electrochemical coupling of hydrogen oxidation and nitrate reduction half-reactions, each of which occurs on one metal component.

C–H activation in organic chemistry usually relies on precious and toxic transition metals. Now it is reported that a sustainable photo-promoted iron-catalysed aromatic imine C–H alkenylation reaction with alkynes circumvents previous limitations of related iron-catalysed reactions that required additives or high reaction temperatures.

The direct cross-electrophile coupling of (hetero)aryl halides and pseudohalides is challenging. Now this reaction is facilitated by a visible light-induced palladium catalytic system that differentiates the reactants on the basis of the bond dissociation enthalpy affording unsymmetrical (hetero)biaryls.

Chemoenzymatic cascade reactions are often hindered by catalyst incompatibility. Now, the co-packing of catalyst-loaded Pickering emulsion droplets and solid microspheres into a continuous-flow column reactor leads to efficient combination of homogeneous, heterogeneous and enzymatic catalysts.

[Cu(phen)(binap)]⁺ features a relatively high photocatalytic activity, but its low photostability hinders its use in organic chemistry. Now immobilization of this motif on a metal–organic framework matrix enhances its stability and excited-state lifetime, enabling the promotion of [2+2] cycloadditions of styrenes with a variety of olefins, including electron-deficient alkenes.

Catalytic conjunctive cross-coupling for the generation of densely functionalized sp³-rich scaffolds that are often found in biologically active compounds is underdeveloped. Now, iron-catalysed dicarbofunctionalization of olefins with dialkylzinc and haloalkanes provides access to synthetically challenging C(sp³)-rich molecules.

The electrochemical synthesis of organic acids is often performed in alkaline electrolytes. This Analysis presents a techno-economic analysis highlighting the challenges involved in using such electrolytes for downstream product separation and electrolyte recovery.